Electronic structure ofRuS2

The electronic structure of the pyrite material ${\mathrm{RuS}}_2$ was investigated with use of self-consistent band-structure calculations and x-ray photoemission experiments. Short-range interactions are found to determine the grouping of bands, consistent with molecular-orbital and crystal-field analyses discussed in the literature for the related material ${\mathrm{FeS}}_2$. The occupied bands have small dispersion. However, the bottom of the first conduction band at the center of the Brillouin zone is found to have appreciable dispersion as characterized by an effective mass of approximately 0.5$m_e$.